600 degrees isn't hot enough with the wire sizes we use. The wires absorb the heat so rapidly the joint doesn't get the right amount of heat. I use the blue hakko station that looks like an old radio and I don't get the solder joints that I like until I run it at about 800 degrees. Sure you can leave the 600 degree tip on the joint forever but that heats the electronics up for too long and that isn't good. I like to be able to be on and off the connection in about 5 seconds...